A fixed caliper brake of this type is disclosed in DE 41 31 130 A1 (offenlegungsschrift). With this fixed caliper brake, the two brake linings are arranged on both sides of the brake disk inside a shaft within the brake housing in such a way that they can be removed radially and, with the aid of hydraulic operating devices present on both sides of the brake disk, can be pressed against the brake disk. The brake linings are axially guided by means of a holding pin and, for the transfer of the peripheral forces during the braking process, they rest tangentially on axially extending, protruding lining supports inside the housing. The disadvantage with such brakes lies in that they produce a considerable amount of noise during braking. This noise production is due to the generation of vibrations in the entire brake arrangement due to fluctuations in the frictional force between the brake lining and the brake disk. In particular, the compact and rigid construction of fixed caliper brakes enhances the transfer of vibrations and may not be able to sufficiently counteract the noise production. Consequently, in the past, steps have been taken for counteracting brake noises of various types. For example, damping layers or metal sheets are frequently applied to the reverse side of the brake linings which, however, incurs additional costs.
In EP 0 163 030 B1, additional brake linings are disclosed which may be used, for example, in a fixed caliper brake of this type and which have through-holes in the lining's backing plate which are filled with the friction lining substance. However, these through-holes do not so much serve for the reduction of noise but, rather, for preventing the friction lining from being cut by the backing plate.
Furthermore, from the documents DE 37 36 126 C2 and DE 40 36 401 A1, antivibration substances are known which are mounted at the brake housing, influence the vibratory behavior of the entire brake arrangement and are used to reduce the generation of noise. However, here, it is necessary to tolerate the resulting increase in the overall dimension of the brake.
The objective of the invention lies in a reduction of the noise development in connection with fixed caliper brakes by means of specific steps taken at the brake housing as well as at the brake lining, which influence the vibratory behavior of the entire brake arrangement without the need for further structural components or the addition of more weight to the brake.
In principle, the invention consists in that the rigidity of the material is specifically reduced at suitable locations at the brake housing or also at the brake linings in order to create partial systems at the brake which can vibrate in a damped manner, reduce the total vibration of the fixed caliper brake and check the noise development.
Preferably, the tangential support of the brake linings is constructed inside the brake housing in such a way as to permit vibrations since these brake linings are directly affected by the generation of vibrations. For this purpose, one embodiment of the invention provides an axially extending peg as a lining support which can vibrate radially as well as tangentially.
In another embodiment of the fixed caliper brake, the axially extending support of the lining has on the side facing the hydraulic operating device a radially extending groove, which reduces the rigidity of the housing in the axial direction.
In addition to the steps taken at the brake housing, above all, the rigidity of the lining's backing plate is reduced by the provision of through-holes. These through-holes are located near or directly at the tangential front face of the backing plate and are filled either with a friction lining substance or with another material with good damping properties. The remaining radial flanges of the lining's backing plate, together with the filled-in through-holes, form tangentially effective, damped vibration systems which, during braking, transfer the generated vibrations in greatly damped form.
In addition to the friction lining substance, as a filler material for the through-holes, preferably inlaid synthetic parts are provided which, in one variation, are introduced directly at the tangential front surface of the backing plate of the lining into the respective through-holes, i.e., precisely at the point that is resting against the lining support while forming an integral part of the housing. This results in the most considerable damping effects.
In a further development of the fixed caliper brake, at least one vibration damper is provided at the brake housing, forming a one-piece connection with the brake housing. This vibration damper is able to vibrate with respect to the brake housing and, in this way, is capable of reducing the total vibration of the fixed caliper brake. The connection of the vibration damper takes place directly during casting of the brake housing with the aid of a flange having a small cross-section or being cast on in crude form followed by shaping of the cast housing through a cutting process.